/* Copyright (C) 2000 MySQL AB

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

#ifndef _tree_h
#define _tree_h
#ifdef __cplusplus
extern "C"
{
#endif

#include "my_base.h" /* get 'enum ha_rkey_function' */

/* Worst case tree is half full. This gives use 2^(MAX_TREE_HEIGHT/2) leafs */
#define MAX_TREE_HEIGHT 64

#define ELEMENT_KEY(tree, element) \
  (tree->offset_to_key ? (void *)((byte *)element + tree->offset_to_key) : *((void **)(element + 1)))

#define tree_set_pointer(element, ptr) *((byte **)(element + 1)) = ((byte *)(ptr))

#define TREE_NO_DUPS 1

  typedef enum
  {
    left_root_right,
    right_root_left
  } TREE_WALK;
  typedef uint32 element_count;
  typedef int (*tree_walk_action)(void *, element_count, void *);

  typedef enum
  {
    free_init,
    free_free,
    free_end
  } TREE_FREE;
  typedef void (*tree_element_free)(void *, TREE_FREE, void *);

#ifdef MSDOS
  typedef struct st_tree_element
  {
    struct st_tree_element *left, *right;
    unsigned long count;
    uchar colour; /* black is marked as 1 */
  } TREE_ELEMENT;
#else
typedef struct st_tree_element
{
  struct st_tree_element *left, *right;
  uint32 count : 31, colour : 1; /* black is marked as 1 */
} TREE_ELEMENT;
#endif /* MSDOS */

#define ELEMENT_CHILD(element, offs) (*(TREE_ELEMENT **)((char *)element + offs))

  typedef struct st_tree
  {
    TREE_ELEMENT *root, null_element;
    TREE_ELEMENT **parents[MAX_TREE_HEIGHT];
    uint offset_to_key, elements_in_tree, size_of_element, memory_limit, allocated;
    qsort_cmp2 compare;
    void *custom_arg;
    MEM_ROOT mem_root;
    my_bool with_delete;
    tree_element_free free;
    uint flag;
  } TREE;

  /* Functions on whole tree */
  void init_tree(TREE *tree, uint default_alloc_size, uint memory_limit, int size, qsort_cmp2 compare,
                 my_bool with_delete, tree_element_free free_element, void *custom_arg);
  void delete_tree(TREE *);
  void reset_tree(TREE *);
  /* similar to delete tree, except we do not my_free() blocks in mem_root
   */
#define is_tree_inited(tree) ((tree)->root != 0)

  /* Functions on leafs */
  TREE_ELEMENT *tree_insert(TREE *tree, void *key, uint key_size, void *custom_arg);
  void *tree_search(TREE *tree, void *key, void *custom_arg);
  int tree_walk(TREE *tree, tree_walk_action action, void *argument, TREE_WALK visit);
  int tree_delete(TREE *tree, void *key, void *custom_arg);
  void *tree_search_key(TREE *tree, const void *key, TREE_ELEMENT **parents, TREE_ELEMENT ***last_pos,
                        enum ha_rkey_function flag, void *custom_arg);
  void *tree_search_edge(TREE *tree, TREE_ELEMENT **parents, TREE_ELEMENT ***last_pos, int child_offs);
  void *tree_search_next(TREE *tree, TREE_ELEMENT ***last_pos, int l_offs, int r_offs);
  ha_rows tree_record_pos(TREE *tree, const void *key, enum ha_rkey_function search_flag, void *custom_arg);

#define TREE_ELEMENT_EXTRA_SIZE (sizeof(TREE_ELEMENT) + sizeof(void *))

#ifdef __cplusplus
}
#endif
#endif
